Backspacing mechanism



Aug. 2, 1949. c. w. NORTON BACKSPACING MECHANISM s Sheets- Sheet. 1

Original Filed July 8, 1944 WM-rm V ATTORNEYS Aug. 2, 1949. c. w. NORTONBACKSPACING MECHANISM Original Filed July '8, 1944 5 Sheets-SheetINVENTOR (fiarlar E Jlormz 5 Mn fm Mm A Patented Aug. 2, 1949 UNITEDSTATES PATENT OFFICE BACKSPACING MECHANISM Charles W. Norton, WestOrange, N. J., assignor to Ralph C. Coxhead Corporation, New York, N.Y., a corporation of Delaware This invention relates to typewritingmachines and as illustrated and described is embodied in a machine knownin the art as a Varityper, in which a supporting anvil carriesinterchangeable type shuttles, so that various styles and sizes of typemay be used at will. This application is a division of my applicationSerial No. 543,981, filed July 8, 1944, now issued as Patent No.2,405,974.

Machines according to this invention are capable of producing typedsheets in simulation of ordinary printed matter which may be used asmake ready for reproduction of photolithographic or other printingprocesses. The printing type, however, must be given variousconventional dimensions as to width, and it is desirable that differentstyles and sizes of type, such as occur in ordinary printed matter inthe way of headings, emphasis and the like, may be used. Means forattaining this result is disclosed in my Patent No. 2,298,805, issuedOctober 13, 1942.

The invention disclosed herein is capable of producing a typed sheet incharacters of conventional dimensions differentially spaced in manydifferent fonts of type; to accomplish this result requires newstructures in respect of some of the functions, and a novel coordinationof the different mechanisms and'devices which must be conjointlyemployed; and it provides mechanism whereby the carriage feed may beadvanced according to the varying width of the different characters, andat the same time affords means for appropriate back-spacing adapted tothe requirements of such difierential spacing.

The object of this invention is to provide improved back-spacingmechanism whereby the carriage may be back-spaced different distancesper stroke.

In the claims as well as in the description parts are identified byspecific names for convenience, but such nomenclature is intended to beas generic, in its application to analogous parts, as the prior art willpermit. The best form in which I have contemplated applying my inventionis illustrated in the accompanying drawings forming a part of thisapplication in which:

Fig. 1 is a plan view of a preferred form of typewriting machine withsuch parts omitted as are well-known in the art and may not be necessaryto a complete understanding of the present invention.

Fig. 2 is a vertical section on the line 33 of Fig. 1.

Fig. 3 is a broken perspective view of the backspacing key andmechanism.

9 Claims. (Cl. 197-91) Fi 4 is a view in side elevation of the twobuttonback-spacing key.

Fig. 5 is a side elevation of the back-spacing ratchet in the positiontaken in back-spacing four units.

Fig. 6 is a detailed view of the escapement dog and a portion of theescapement wheel that is acted upon by the back-spacing mechanism.

Fig. 7 is a plan view of the back-spacing ratchet shown in Fig. 3.

The machine herewith illustrated and described is of the key-controlledshuttle type, where the printing impression is formed by the impact ofa.

printing hammer which forces the paper against the ribbon and type. Theparticular machine illustrated is known in the art as the Varityperi,Referring to Fig. 1, it comprises a main frame I which carries themechanism of the machine.

Type keys 2 (only a few being illustrated) are mounted on a pivot bar 4(Fig. 2) supported by the main frame l. These type keys 2 at their frontends carry finger buttons 5 and at the rear ends cooperate with theactuator bars 6 (one of which is shown in Fig. 2) to operateactuators 1. These actuators 1 swing the shuttle arm 8 (Fig. 1) so thatit oscillates the shuttle 9 on an anvil 9a to bring the proper type tothe printing point.

This mechanism is old in the art and will not be described in detail.See patent to Trego No. 1,880,592, October 4, 1932.

The paper carriage l6 (Fig. 2) is provided with antifriction rolls I!which travel upon the carriage supporting rod l8 as the carriage movesto the left under the influence of the carriage spring. This mechanismis also old and well-. known in the art and therefore will not bedescribed in detail. The carriage is moved in letter space direction bya carriage spring which is mounted in a drum [9 (Fig. 1) that carries aband which is attached to the carriage, as is well-known in the art.

The carriage I6 is progressed from two to seven units of space upon theprinting of a character or symbol, the exact spacing being dependentupon the width of thecharacter. For example, a lower case L is allocatedthree units of space, while the lower case M or W is allocated sevenunits. This variable spacing in accordance with the width of the lettersoccurs within the same font of type. The unit of space referred to is anarbitrarily selected unit which is an aliquot part of and smaller thanany of the letter spaces. The term "letters as used herein includes thevarious symbols and figuresfound on a typewriter keyboard, as well asletters of the alphabet.

dotted-line position and contacts frame I of the machine, therebypreventing further downward movement. This limited movement is designedto effect only one backspacing unit. The button 5 312 is marked Backspace 1.

The motion ,ofithe backspacing;-key 3' is communicated to theescapemenfmechanism-by shaft I3, mounted in the frame I. This shaft hasrigidly secured thereto an arm carrying the roller and r space ni s r piv lyyI =-llwtinacontaet with extension 3e on the backmechanism,escapement wheels I- IIf and IV-- are selectively orsimultaneously-released for rotation of a single tootlf'upomd'pressiowofa printing key 5. The details of consh'uction bt spacing key. On therear end of shaft I3 there isrigid1yi'secured4amarm I3b (see Fig. 3)connectedby;'a'1irrl:I3c7 with a bell-crank lever I3d freely mountedforoscillation on escapement wh h h va a le sp azis a m s d are'llifisha'ftt I Ii Theearmalsb and link I30 are biased set forth indetail in the above-reirredi'ttorparenti; application.

A system of variable letter spacing of the type above describedrequiress that the backspacing mechanismubencapable of backspacing thecarriage IBfor any numherpfspace'unita In'order that the carriagermay bereturnedifortherretyping ofiany characten or ,symbol whichmaybepoorly orillegibly printed, or forthe maintenance of an;

indented column, as well .asv for otherreasons;

it ;'is..essential Tto provide. backspacing mechanism which. is,capable.ofibackspacing; one unit only: Flor: greater .speediimbackspacing; itis desirable to also provide additional'mechanismior;back= b yia springl 3d tending to draw them toward each other;the effect ot which is tobias shaft I3 in suchimanner as to maintain roller I3a in contact withthe extension 36 on the back-spacing key, and to bias bell-crank leverI3d toward the positionshown'in'Fig; 3, which is the normalordn-active:position'.of-th'e"mechanism.*

A pawl-i23is pivoted on-a pin-23a; rigidly-se cured*to:the-bell-'cranklever I3d1' 'Ihe-pawl n'! is 'spacedfrom' thebell crank I311 flay asleeve 231), as is" shown in Fig. 7* (with the spring: 232% omittedd Itis to-beobserved: that both b'ell I crank lever I 3d-and*escapementwhee1-*-If are freelymounted on escap'ement shaft -4 I and that spafigethemarriagea pl m y, of spacet nits: the -sleeve-23bserves-td-position 'pawl 23 for co=-- Toaneet this need therbackespacingkev 3"'(Fig; 1) hastworbuttons; 3Z1 and.3b3, one .,of i'which operates"toeliackspaceiour at each stroke, andlthe other; oftlwhiohloperatesatobackespace: azsing1e;

actiorrwith the'teethon escapement wheel I -j. Toobtain--properengagement b'etweem the pawl 23"and theteeth-of theescapement wheelI -f,sleever23b has"aprojecting pimfle *(Fig: 5-)"whic l'iunitonleaoh;stroke.. Itjisd-essentialfin, suclicase: 85 engages'pin 2311mmpawl23 andimparts thereto thatbackspacing befieeirom mechaniealerror; and;theback-spacing. mechanism is so con-1 stmotedcasctoesecune,exactspacing. ItLLisl com-- strueteditoact zuponaessapement .Wheel" I f.' Iti the pressure-of springfl3e surrounding=sleeve 23band atta'ched' atone-= end to the belI- orank I 3?? arid" at the other" endto-"p in -23aWhicl'i'spring" tends to h'oldthepawlin engagement with z the willlb'eseen 'oru'efe'renceioiEig. 6 that the eescapee- 40" escapement wheelment wheel 'I;'-f.- isrcontrolledr by, the actiornof; dogs I 05 and, I06.1 The-action.of."typing a char: aeteroperatesrtoerelase dog l05Ifromthe escapee meat wheels. When-.theldogd 05 is being released}.

However; in normal or='inactive=position (Fig. 3') pawl 23 isout ofengagement witlr escape-"- ment Wh'eeI I- f: and it 'is'held -in"thisinactive position by a pin" 43 secured on the: machine th'e-d0g=. l061s; irmthecpafli ofianeoncomin stooth- 5- fr m -s Whichpin en a es an0tch= 43a-:in-*p w ofi; the escapemen-t wheel-1 before thatwheeli. is:entirely =freeeffom.-theedog- 1 I 05; ,andithel-irelationl OffiOgJflliandtdog l 05Tislsuch as .tmpermit a=.very;.. slight 'movement of theeseapemenLwheeL-after,

dege I llfiehasubeenldisengagedand beforeuth'eeescapemenit' wheelshassb'eenstopneiby, dog" !06.. Wh'emdog: I UBLrelasesthe escapemenhwheel,itfisrre=engaged by, dog I05; and therescapement wheelhasrturneioneltooth,ppogressingathel car:

23?- Ii'r this=posltion escapement wheel I 4; being under tlieinfiiience of the -carriagedrive, is: controlTed -in its rotationpartly-bycdog- Ifl5' and partly-by -*dog= I 86}. as *been explained."

Dog I05 carries=a-pif1 mm: which is engage abl=by wpih- IIISUwmlirr-kI30 wherr'in the-post tion shown 'inF'ig'r- 5? Ifvtliat positionthe *extension I3i on bell-cranklever' I3cl' contacts? stoppin=63 "on"-themachine =frame5 Thepurpose riageJtl'oneeunitd A-more.detailed-de'scription, of this contact is= to=take the-principal"shockof of: this escapementemechanism ia containedain, theabove-mentioned; parent application. The. hackspacing mechlanismnof;Eig,..3lis ,designed.'to actuate theeescapementfwhleel I;-f 'in .thereverse direction. 7

The.buttonsemiarid3bv (Eigsa3 and .4). arecarried. by a. member;pivoted) 0n..the key. 3;. member is. yieldably held" inl the. positiomshown imFZigbrllbyaatensionnspringjfil Itlh'asa .pointrorr the -backspacing stroke and-"th ns -:protect the dog I05 and the pins 15a andI05b as wellaszthew escapementrwheelffom excessive force arrd in- Whenthe -keydi riS given'zai: fu1-1 wstrokersothat'. it contacts: the. stop:pina 3d= the backs-spacing: meehamsmwwillitakeethe position shown inFig.7 5;- in= whichpin 15b contacts pinzIIISwand. so.holds-.- dogs, I05am vcontact LWj-th ,artooth of ,escapement w g mcm dgwnwardmgyementofj h key 65' wheel If. This wi1l.preventanyrfiirthenback=- lmpressureombutton 3a issnotchangedjn pOSL:

tionbut clearsithejrame ,I landQpermitsthe key 3.tormove.downwardmntilitnontactsizheadjustable stope3da Thissmovementeflectsi an backespacingg ward .rotation ;of the escapement. wheel atthe endof theofflllstrok'e; and the movement is such thattheescapement'wheel has moved backward a" distance equal to four--andone=half fteeth beohfoumvunitmaanibuttonfid isimarkeareaea 'f0refarther nwvementi'issstopped. O -the re= space 4:." If,;,however, .thekey. isoperated; by pressure .on-tbutton 3b.the.pivoted member, which.carriescthev operating buttons,. is first deflected againstthertensionot-ithe spring BLandbnrdGWne turn of the mechanism, dog I05will permit/ a forward rotation oftl'ie'escapement wheelfor-*a distanceof half a tooth, when the next tootl'rwill be engaged'by'dog I 05: Theresultant backward ward movement of'the key 3, toe 3?: takes the motionof the full baclr=spacing-stroke'is'a baclr ward movement of four teethof escapement wheel 1-). This rotation transmitted through the train ofescapement gearing (shown in Fig. 2) results in an angular rotation ofshaft 4| which is the equivalent of four spacing units.

Obviously a backward movement of only one tooth would transmit to shaft4| a movement of only one unit; and this is the backward movementoccasioned by a stroke on button 31).

It is to be observed that when the back-spacing key is released and thepawl 23 returns to its normal position the spring 23c permits the pawlto move outward as it passes over the ratchet teeth; and as itapproaches pin 43, notch 43a is in position to engage pin 43. Furtherreturn movement of the pawl completely disengages it from th teeth onescapement wheel 1- In order to avoid friction and noise on carriagereturn the escapement mechanism is provided with a construction thatlifts the dog I of escapement wheel I-f at this time. I'his comprises agrooved wheel 13 around which is a bight of strand material, in thisinstance spring wire 13a, frictionally engaging the bottom of the grooveand terminating in a bent end 13b (Figs. 3 and 5). The grooved wheel 13is fixedly mounted on shaft 4| and turns counterclockwise on returnmovement of the carriage. The spring [30. rotates with the wheel I3until the end of this spring engages pin I 05a (Fig. 5) and earnsoutwardly the pin a carried on the dog I 05, thus removing the dog I85from engagement with the escapement wheel I-). When the carriage movesin letter space direction the spring 13a is carried along with wheel 13,restoring the normal action of dog I05. When the end 1312 of the springengages the fixed pin I050 the spring tends to open around grooved wheel13 so that no perceptible friction occurs during letter space travel ofthe carriage.

It is to be understood that while the invention is described herein asapplicable to a typewriting machine of the kind known as a Varityper itis capable of use with typewriting machines of other kinds, and is notto be understood as limited in its scope other than is indicated in theclaims.

What I claim is:

1. In a typewriting machine, in combination, a movable paper carriage, aspacing mechanism for controlling the movement of said carriage, aback-spacing key lever, an oscillator shaft, an arm rigid on said shaftadapted to contact said back-spacing key lever, a second arm rigid onsaid shaft, an escapement shaft, a member freely oscillatable on saidescapement shaft, 3, link connecting said second arm with said member, aspring operative to hold said first mentioned arm in contact with saidback-spacing key lever, an escapement wheel mounted on said escapementshaft and connected therewith, a pawl pivoted on said member foractuating said escapement wheel, and means controlled by said link forpreventing overthrow of said escapement wheel at the end of itspawl-actuated movement.

2. In a typewriting machine, in combination, a movable paper carriage, aspacing mechanism for controlling the movement of said carriage, aback-spacing key lever, an oscillator shaft, an arm rigid on said shaftadapted to contact said back-spacing key lever, a second arm rigid onsaid shaft, an escapement shaft, a member freely oscillatable on saidescapement shaft, a link connecting said second arm with said member,

a spring operative to" holdsaid first mentioned arm in contact with saidback-spacing key lever, an escapement wheel mounted on said escapementshaft and connected therewith, a pawl pivoted on said member foractuating said escapement wheel, saidpawl being normally held out ofcontact with said escapement wheel, and means 1 controlled by said linkfor preventing overthrow of said escapement wheel at the end of itspawl-actuated movement.

3. Ina typewriting machine, in combination, a movable paper carriage, aletter spacing mechanism operable within the same font of type andincluding a plurality of interconnected escapements operable selectivelyor combinationally for variably controlling the carriage movement inaccordance with the width of letters within a single font of type, oneescapement being effective to space an aliquot amount of any of thecarriage letter spacings, and backspacing mechanism for'backspacing saidone escapement a like aliquot amount.

4. In a typewriting machine, in combination, a paper carriage, 'a letterspacing mechanism operable within the same font of type andincludingthree interconnected escapement-s selectively operable forvariably controlling the carriage movement, one escapement beingeffective to space an aliquot amount of any of the carriage letterspacings, and back spacing mechanism for backspacing said one escapementa like aliquot amount.

5. In a typewriting machine, in combination, a paper carriage, a letterspacing mechanism operable within the same font of type and includingthree interconnected escapements operable selectively or combinationallyfor variably controlling the carriage movement, one escapement beingeffective to space an aliquot unit less than any of the carriage letterspacings, and backspacing mechanism for backspacing said one escapementa like aliquot unit.

6. In a typewriting machine, in combination, a movable paper carriage,an escapement mechanism, including an escapement wheel, for controllingthe spacing movement of said carriage, a backspacing key lever, a pawloscillatable about the axis of the escapement wheel, said pawl beingnormally held out of engagement with said wheel and engageable therewithupon oscillatory motion of the pawl for backspacing the carriage, meansoperatively connected with said backspacing key lever for oscillatingsaid pawl, and an escapement-wheel-engaging means actuated by said pawloscillating means at the end of its carriage backspacing travel toprevent overthrow of the escapement wheel by said pawl.

'7. In a typewriting machine, in combination, a movable paper carriage,an escapement mechanism, including an escapement wheel, for controllingthe spacing movement of said carriage, a backspacing key lever, a pawloscillatable about the axis of the escapement wheel, said pawl beingnormally held out of engagement with said wheel and engageable therewithupon actuation of the backspacing key lever for backspacing thecarriage, means operatively connected with said backspacing key leverfor oscillating said pawl, and an escapement-wheel-engaging meansactuated by said pawl oscillating means at the end of its carriagebackspacing travel to prevent overthrow of the escapement wheel by saidpawl.

8. In a typewriting machine, in combination, a movable paper carriage,an escapement mechanism, including an escapement wheel and a dog ammonormally engageditherewith, ior controlllng the spacing movement of-sazldearriage, a backspacing key lever, a pawl-'oscillatable aboutthe-axis of the esc'apement WheeLsa-id pawl being normally held outofengagement with said wheel and engageable therewith uponoscillatory'motion of the pawl to movethe iescapement wheel inreversedire'ction, said dog being displaceable by reverse movement ofthe escapement-wheel, and means operatively connected with saidbackspacing key lever for oscillating said pawl and restrictingdisplacing movement of said dog at the end of the pawlsscarriagebackspacing travel to prevent overthrow of the escapement wheel by'saidpawl.

9. In a typewriting machineyin combination, a movable paper carriage, anescapement mechanism, including an escapement wheel and a dog normallyengaged therewith, for controlling the spacing movement of saidcarriage, a backspacing key lever, a pawl oscillatableaboutthe axis ofthe escapement wheel, saidpawl being normally held out ofengagement withsaid wheel and engageable therewith upon oscillatory motion of the pawlto move-theescap'ement 'wheel in reverse direction, said :dog beingdisplace'able by reversem'ovement or the escap'ement vwheel,

and-a link operatively connected with said backspacing key lever tocause oscillation of said pawl, said link being adapted to restrict thedisplacing movement of said dog at the end of the pawls backspacing.travelto prevent overthrow of the escapement wheel :by said pawl.

CHARLES W. NORTON.

REFERENCES CITED "Ihe following'refe'rences are of record in thefileofth'is patent:

UNITED STATES PATENTS Number Name Date 656,658 Phelps Aug. 28, 1900604,073 Peterson Feb. 25, 1902 1,183,056 Wiley May 16, 1916 1,243,955Krusius Oct. 23, 1917 1,918,304 Trego July 18, 1933 1,941,018 MurrayDec. 26, 1933 1,984,410 Hart Dec. 18, 1934 2,127,431 Schremp Aug. 16,1938 2,224,766 Dodge Dec. 10, 1940 2,268,867 Gabrielson et a1. Jan. 6,1942 2,294,721 'Dobson Sept. 1, 1942 2,364,653 Pollock et a1. Dec. 12,1944

